Make the length of SingletonSocket's path as short as we can

chromium_src/chrome/browser/process_singleton_posix.cc

@@ -111,7 +111,7 @@ const base::FilePath::CharType kSingletonCookieFilename[] =
 
 const base::FilePath::CharType kSingletonLockFilename[] = FILE_PATH_LITERAL("SingletonLock");
 const base::FilePath::CharType kSingletonSocketFilename[] =
-      FILE_PATH_LITERAL("SingletonSocket");
+      FILE_PATH_LITERAL("SS");
 
 // Set the close-on-exec bit on a file descriptor.
 // Returns 0 on success, -1 on failure.
@@ -943,6 +943,19 @@ bool ProcessSingleton::Create() {
 #endif
   }
 
+#if defined(MAS_BUILD)
+  // For Mac App Store build, the tmp dir could be too long to fit
+  // addr->sun_path, so we need to make it as short as possible.
+  base::FilePath tmp_dir;
+  if (!base::GetTempDir(&tmp_dir)) {
+    LOG(ERROR) << "Failed to get temporary directory.";
+    return false;
+  }
+  if (!socket_dir_.Set(tmp_dir.Append("S"))) {
+    LOG(ERROR) << "Failed to set socket directory.";
+    return false;
+  }
+#else
   // Create the socket file somewhere in /tmp which is usually mounted as a
   // normal filesystem. Some network filesystems (notably AFS) are screwy and
   // do not support Unix domain sockets.
@@ -950,6 +963,7 @@ bool ProcessSingleton::Create() {
     LOG(ERROR) << "Failed to create socket directory.";
     return false;
   }
+#endif
 
   // Check that the directory was created with the correct permissions.
   int dir_mode = 0;